I was going to buy a cheap Feeltech, but some have reported that its lack of proper grounding is allowing voltages of around 90 volts at 1 milliamp to run through the probes. Concerns have been raised about connecting it to mpus and such. So I was kind of resigned to swapping out the internal power supply for something better, which is expensive and bothersome.

Let's see what I remember. A full color LCD display on the front. Power through a wall wart, so no high voltage transients running around. Some very nice software that appears to do a lot more than the remote control software for the Feeltech. A whack of pre-programmed waveforms, most of which have names I don't recognize. A proper sine wave up to 25Mhz. And apparently some decent square and triangle waves up to 15Mhz (the feeltech crapped out around 4Mhz). The ability to store up to 60 different user defined waveforms, as well as sample an incoming wave form. Dual channel outputs.

There are a ton of specifications on the site. I won't pretend to know whether they're significant. I'm hoping you folks do.

They want $140 Canadian including e-packet shipping (which is pretty fast). The Feeltech was $85, plus whatever I have to do to solve the voltage transient problem.

I have the impression that this thing is somewhere in between the Feeltech cheapie, and a name brand signal generator from Rigol et al.

I'm leaning towards buying one. I'd sure appreciate feedback from all of you. Or any of you.

I've been planning a YouTube channel for about a year - or more - now. I have a lot of cool DIY projects that center around 3D printing, and a lot more - like a review of the JDS 6600, and an updated review on the Korad power supply - centering around electronics. With my Wriggle DS1054Z arriving tomorrow, I'll have a decent scope to test them on. I'm also building a really simple UV contact printer to allow me to make some PCBs. So there's a lot of topic material there.

Yes, I'll be doing a bit of a teardown on the 6600 when it shows up - at least enough to show people what's in the case - and some decent testing of the signal quality vs frequency. I'm not expecting a great deal, but i hope that it's better than Feeltech. I'll be disappointed if it's not.

I ordered one of these about 10 days ago. According to Canada Post, they received it a few days ago, but haven't done anything with it.

However, the unit is on sale right now. I paid $136.86 CAD; the current price is $123.50 CAD, so maybe 10% off or so. Or a little more; I think their regular price was $140 CAD, but I got a few bucks off for being a nice guy. Heh, heh. Little do they know.

Anyway, mine hasn't arrived yet, so I can't endorse it. But for any one who was on the fence about ordering one, you can get it for 10% off right now.

It's also worth noting that they've introduced several new models; they now claim a new high frequency of 60Mhz on their most expensive model. This is for a sine wave. For square or triangle waves, they claim a maximum of 15Mhz across the board, for all their models.

From testing the FY3200 myself and reading on the MHS5200 they both are both limited in their output voltage range into 50 Ohm load without clipping or high distortion. So the first test I would suggest is:

1. Set 10 KHz sinewave with 20 Vpp/maximum amplitude on an oscilloscope with 1 Meg impedance. Then add the 50 Ohm termination and see if the output drops to 1/2 or if clipping or distortion starts happening.

On these type generators the output buffer is often slew rate limited which in turn means the output amplitude at higher frequencies is limited. So, the second test I recommend is:

2. Set a 10 Vpp 100 kHz sinewave on the output into oscilloscope with 50 Ohm termination. Then increase the frequency until maximum frequency to see if or at what frequency it starts distorting horribly.

On the FY3200 generator when you change the frequency the output waveform glitches. Ideally one would expect a change in frequency with a sine wave to step change the slope at the frequency change with no step in the actual voltage. Unfortunately the FY3200 has steps in the output because the phase as well as the frequency changes when you change the frequency. So, the third test I would love to see is:

3. Set the generator to 5 Vpp, 10 kHz sine wave and then step change the frequency to 20 kHz. Try to capture on the oscilloscope the moment when the frequency changes. If you have advanced triggering I set trigger width must be < 20 uSec and then set to capture once.

When you use two channels both outputting the same frequency sine wave with the phase 90 Deg apart it would be great to repeat test 3 to insure that both channels change frequency at the same time and with no glitches.

The triangle waveform looks quite good - better than I remember from the MHS5200. However the scope setting is not that good to tell if the little nonlinearity is from the scope of from the generator. If would need a zoom in on details of the slope and maybe an even lower frequency. Usually a simple R2R DAC would show visible errors near the center or 1/4 of the range. There are 2 pots for each channel so these might be for adjusting at least that largest error.

The picture of the circuit is just to bad in resolution to read the chip numbers. The output amplifiers might be interesting. For the rest I would expect an AD603 or similar for the amplitude adjustment.

Are the USB and TTL I/Os isolated from the normal outputs ? It does not look like.

From testing the FY3200 myself and reading on the MHS5200 they both are both limited in their output voltage range into 50 Ohm load without clipping or high distortion. So the first test I would suggest is:

1. Set 10 KHz sinewave with 20 Vpp/maximum amplitude on an oscilloscope with 1 Meg impedance. Then add the 50 Ohm termination and see if the output drops to 1/2 or if clipping or distortion starts happening.

1 meg impedance, max amplitude @ 10KHz:

50 Ohm termination:

Quote from: gby

On these type generators the output buffer is often slew rate limited which in turn means the output amplitude at higher frequencies is limited. So, the second test I recommend is:

2. Set a 10 Vpp 100 kHz sinewave on the output into oscilloscope with 50 Ohm termination. Then increase the frequency until maximum frequency to see if or at what frequency it starts distorting horribly.

So I think there are 2 interesting points here, at 10MHz and at 25MHz. Because above 10MHz the amplitude is restricted down from 20Vpp to 10Vpp (probably for slew rate reasons).

At the maximum frequency useable at 20Vpp (into 50 Ohms, so we should be seeing 10Vpp):

So that second harmonic is at about -30dBc, which is out of spec (Spec says -40dBc).

At 25MHz, it looks a bit cleaner (but the amplitude is now 10Vpp out, which should look like 5Vpp into 50 Ohms):

And an FFT:

Looks to be about -40dBc, so that's roughly in spec.

Quote from: gby

On the FY3200 generator when you change the frequency the output waveform glitches. Ideally one would expect a change in frequency with a sine wave to step change the slope at the frequency change with no step in the actual voltage. Unfortunately the FY3200 has steps in the output because the phase as well as the frequency changes when you change the frequency. So, the third test I would love to see is:

3. Set the generator to 5 Vpp, 10 kHz sine wave and then step change the frequency to 20 kHz. Try to capture on the oscilloscope the moment when the frequency changes. If you have advanced triggering I set trigger width must be < 20 uSec and then set to capture once.

Here's what that looks like:

Slightly zoomed in:

Quote from: gby

When you use two channels both outputting the same frequency sine wave with the phase 90 Deg apart it would be great to repeat test 3 to insure that both channels change frequency at the same time and with no glitches.

I couldn't find a way to change the frequency of both channels at once, so I'm not sure if that's possible. Here's what 2 channels at 90 deg phase shift look like when channel 1 is increased in frequency:

Quote from: gby

The last requested test is really just a question of functionality. This generator can do frequency sweeps. But, can it do frequency sweeps while outputting two wave forms? Last requested test is:

5. Can you set the generator to output 2 sine waves with 90 Deg relative phase and then sweep the frequency such that both channels sweep in frequency and stay in phase lock?

In advance I thank you for any of the above tests that you could do and report back results.

As far as I can tell it's not possible to do sweeps on 2 channels at once.

The triangle waveform looks quite good - better than I remember from the MHS5200. However the scope setting is not that good to tell if the little nonlinearity is from the scope of from the generator. If would need a zoom in on details of the slope and maybe an even lower frequency. Usually a simple R2R DAC would show visible errors near the center or 1/4 of the range. There are 2 pots for each channel so these might be for adjusting at least that largest error.

All good points, if I get some time later I might try a super-low frequency and use the datalogging feature on my keysight DMM to get some more precise measurments of that.

Quote from: Kleinstein

The picture of the circuit is just to bad in resolution to read the chip numbers. The output amplifiers might be interesting. For the rest I would expect an AD603 or similar for the amplitude adjustment.

Strange, I can read most of the chip numbers except a couple on the left - if you go to the raw link it should be a higher resolution than what you're seeing on the forum.

From left-to-right with the front end it looks like a bunch of discretes and then (same for both channels):1. An AD8056A 300MHz voltage feedback amp.2. An AD835 250MHz 4-quadrant multiplier.3. An AD8017 160MHz high output drive op amp4. All the relays & discretes as well as:5. A TI part, 3001I. I'm assuming this is the THS3001, which is a 420MHz current-feedback amplifier.

Quote from: Kleinstein

Are the USB and TTL I/Os isolated from the normal outputs ? It does not look like.

The chip between the FPGA and TTL I/Os is just a 74HC14 hex inverter, so probably not.

I haven't been able to identify the chip between the FPGA and the USB port, the code looks like CR3400

1. Looks like they got the output buffer "strength" right this time. The MHS-5200 had too small a power supply voltage to reach full 10 Vpp across 50 Ohm and the FY3200 buffer had to low a current limit. So, the JDS66000 is definitely improved here and from your photograph it looks like a reasonable heat sink.

2. Looks like some slew limiting on the output at 10 MHz but not too bad. The official specs say 20 Vpp up to 10 MHz, 10 Vpp 10 - 30 MHz, and 5 Vpp > 30 MHz. These specs imply a slew limit of just better than 5V0-p*2*pi*30MHz = 942 V/uSec. Probably around 1000 V/uSec which is pretty good.

3. Changing single channel frequency looks to be smooth which is good.

4. For changing the frequency when both channels are running the same frequency you say: "I couldn't find a way to change the frequency of both channels at once, so I'm not sure if that's possible"These generators usually have a channel synchronization mode where you lock them such than changing one channel parameter changes both channels. In the JDS66000 manual I found on line it says under the system setting menu:

4.4.2 Sync: When sync, CH1 is the object of operation. CH2 parameter will be changed with the changes of CH1 parameter. When the sync item is selected, you can press or knob to select the sync item needed, press ON softkey to select and press OFF softkey to cancel.

Could you check for the system setting sync function and try changing the frequency of two channels locked at 90 Deg phase again?

5. Perhaps with the two channels sync'ed you can then sweep two channels with a phase difference simultaneously?? One can only hope....

The parts used seem to be a little more expensive (e.g. AD835 instead of lower cost AD603) than those in the super cheap versions. The amplifiers also look rather fast. Still strange that there are additional AD8017.

I finally found the higher resolution pictures. So I got a look at the DAC: they seem to use 15 lines in a thermometer style to get the upper about 4 Bits with less errors / glitches. So the DAC is not just an R2R ladder.

I ordered one of these about 10 days ago. According to Canada Post, they received it a few days ago, but haven't done anything with it.

However, the unit is on sale right now. I paid $136.86 CAD; the current price is $123.50 CAD, so maybe 10% off or so. Or a little more; I think their regular price was $140 CAD, but I got a few bucks off for being a nice guy. Heh, heh. Little do they know.

Anyway, mine hasn't arrived yet, so I can't endorse it. But for any one who was on the fence about ordering one, you can get it for 10% off right now.

It's also worth noting that they've introduced several new models; they now claim a new high frequency of 60Mhz on their most expensive model. This is for a sine wave. For square or triangle waves, they claim a maximum of 15Mhz across the board, for all their models.

I don't believe the 60Mhz claim. I'm sure there's something there, but I'll bet it winds up looking like a weak, wobbly triangle wave than a pure sine.

Anyway, for someone interested in checking it out... there it is.

>Charlie

because we update our JDS6600. now 15MHz, 30MHz, 50Mhz, 60mhz are new version, there is not any problem for this data, we never sell fake data products, quality is very importanct as our life, you can asy"you don't believe" , but our data is real, only you test it , you have right to say those words, ok?